PNWS-AWWA 2008 ANNUAL CONFERENCE INTRODUCTION TO THE PROPER SELECTION AND APPLICATION OF PROTECTIVE COATINGS Stan Osborne Sr. Industrial Coatings Specialist ICI Devoe Coatings
PNWS-AWWA2008 ANNUAL CONFERENCE
INTRODUCTION TO
THE PROPER SELECTIONAND
APPLICATION OFPROTECTIVE COATINGS
Stan OsborneSr. Industrial Coatings Specialist
ICI Devoe Coatings
SurfacePreparation
andApplication
PNWS-AWWA2008 ANNUAL CONFERENCE
SurfacePreparation
(what you always wanted to know . . .and some stuff you didn't)
PNWS-AWWA2008 ANNUAL CONFERENCE
Cleaning StandardsThe Society for Protective Coatings (SSPC)
Cleaning StandardsThe Society for Protective Coatings (SSPC)
SSPC CleaningStandardsSP1 Solvent Cleaning: Removal of oil, grease, dirt, & salts by
cleaning with solvent, water, detergent, alkali or steam.
SP2/SP3 Hand & Power Tool Cleaning: Removes loosepaint, loose mill scale and loose paint by chipping, scraping, sandingand wire brushing.
SP11 Power Tool Cleaning to Bare Metal: Removal of allvisible oil, grease, dirt, mill scale, rust, paint, and contaminants and toretain or produce a surface profile.
SP 15 Commercial Grade Power Tool Cleaning: Similar toSP 11 but allows some staining to remain and mandates minimum 1mil profile.
SP-1
Chemical cleaning test patches underway
SP-1 Emulsion Cleaning
SP-2
SP-3
SP3SP3
Power Tool Cleaning (Grinding Disk)
SPSP--1111
Power Tool Cleaning to White Metal (Needle Gun)
SSPC Blasting Standards
SP5 White Metal Blast: Removal of all oil, grease, rust, millscale, paint and contaminants by blast cleaning by wheel abraderor abrasive blasting nozzle (dry or wet) using sand, grit or shot.
SP10 Near White Blast: Same as SP5 but 5% of areaallowed residual shadows
SP6 Commercial Blast: Same as SP5 but 1/3 of area allowedresidual shadows
SSPC Blasting Standards
SP14 Industrial Blast Cleaning: Blasting to remove tightlyadhering residues of mill scale, rust and coatings. Traces of residueare permitted on 10% of each unit area if they are evenlydistributed.
SP7 Brush Off Blast: Blasting to remove marginally adheringresidues of mill scale, rust and coatings and provide a properlyprepared surface condition for application of subsequent coatings.
Commercial Blast
Close Up: Commercial Blast
SP 6SP 6
Near White Metal Blast
Close Up: Near White Blast
SP 10SP 10
Close Up: Near White Blast
SP 10 Wheel Abrader using steel grit / shotSP 10 Wheel Abrader using steel grit / shot
Other SSPC SurfacePreparation Standards
SP12 Surface Preparation and Cleaning of Steel andOther Hard Materials by High- and Ultrahigh-PressureWater Jetting Prior to Recoating: Covers severalcleanliness standards.
SP13 Surface Preparation Of Concrete: Covers manydifferent techniques - water jetting, abrasive blasting,mechanical tools, etc.
What are the Goals of SurfacePreparation?
Removing contamination
Providing a surface profile to ensure coatingsadhere
Removing or smoothening irregularities (pits,projections, sharp edges) to allow for uniform filmdevelopment
Removing tightly bound mill scale & rust
To provide a surface suitable for painting by:
What Surfaces Require Preparation?
Iron and Steel
Galvanized Metal
Aluminum
Concrete and Masonry
Pre-Coated Metal Siding
Previously Painted
Iron and Steel
Why Clean?
To Remove:
Mill Scale
Rust
Oil/Grease
Dirt
Soluble Salts
How to Clean:
Solvent Cleaning (SP1)
Hand Tool Cleaning (SP2)
Power Tool Cleaning (SP3, SP11)
Abrasive Blast (SP5, SP10, SP6, SP7)
Water Blast (RP-01-72)
Galvanized Metal
Why Clean?
To Remove:
White Rust
Oil/Grease
Dirt
Soluble Salts
No Profile
How to Clean:
Weathering (takes up to 1 year)
Can’t Wait . . . .
Solvent Cleaning (SP1)
Acid Etching
Hand Tool Cleaning (SP2)
Abrasive Sweep Blast (SP7)
Aluminum
Why Clean?
To Remove:
Oil/Grease
Dirt
Soluble Salts
How to Clean:
Solvent Cleaning (SP1)
Acid Etching (minimal profile)
Abrasive Sweep Blast (SP7) *
*Sweep blast is often done with softer abrasives such as plastic pellets
ConcreteWhy Clean?
To Remove:
Efflorescence
Form Oils
Laitance
Air Pockets
Contaminants
No Profile
How to Clean:
Solvent Cleaning (D-4258)
Brush Off or Sweep Blast(D-4259)
Acid Etch (Floors) (D-4260)
Hand Tool Cleaning (SP2)
Power Tool Cleaning (SP3)
Water Blast (RP-01-72)
Caution: Test moisture content and for presence of concrete hardeners
Pre-Coated Metal SidingWhy Clean?
To Remove:
Wax
Silicone
Dirt
Fluropolymer (Hard& glossy surface of lowpolarity) Kynar Finishes –Marketed as Never Haveto Paint Again
How to Clean:
Solvent Cleaning (SP1)
Sanding (SP2 or SP3)
Abrasive Sweep Blast (SP7)
Caution: An adhesion test patch is recommended
Previously PaintedWhy Clean?
Loose Paint
Oil/Grease
Dirt
Soluble Salts
Rust
Chalk
Hard & Glossy
How Clean:
Solvent Cleaning (SP1)
Hand Tooling - Scrapers, etc.) (SP2)
Sanding (SP2)
Power Tool Cleaning (SP3, SP11)
Abrasive Blast (SP5, SP10, SP6, SP7)
Water Blast (RP-01-72)
Test for adhesion and compatibility
Properties of AbrasivesType
Metallic, Mineral, Slag, Other (sponge,walnut shell, glass beads, etc.)
Hardness
Rate of Breakdown
Size
Shape
Shot Grit
Abrasive BlastingEquipment (Field Set-Up)
In-Shop Centrifugal Blasting(Wheel Abrader)
Relative Surface Preparation Costs
Cleaning Grade Field Shop
SP2 Hand Tool 1.8 0.8
SP3 Power Tool 2.3 0.8
SP7 Brush Off Blast 2.1 ---
SP6 Commercial Blast 3.1 1.0
SP10 Near White Blast 3.6 1.1
SP5 White Metal Blast 4.4 1.2Source: G. Brevort, A.H. Roebuck, “Selecting Cost-Effective Protective Coating Systems”
Data from 2004
Coating SystemSelection
&Performance
Criteria
PNWS-AWWA2008 ANNUAL CONFERENCE
Factors AffectingCoating Performance
Structural Design
Coating Selection
Surface Preparation
ApplicationD
esig
n
Coating
Surf
ace
Prep
.
Application
ProtectionProtection
Structural Design forAggressive Environments
Skip WeldRound All Sharp Edges(1/4 in. (0.6cm) RadiusPreferred, 1/8 in. (0.3cm)Radius Minimum)
Full Seam Weld
DO
DON’T
DON’T
or
Preferred To
Avoid Angles or Channels
Other Design Considerations
Surfaces should be smooth (e.g. welds)
Welding preferred to riveting
All surfaces should be well drained (ie: weepholes installed to drain pockets/cavities
Faying surfaces should be avoided
Stiffening members should be on the outsidesurface of tank or vessel
Corrosion at Skip Welds
Corrosion at Rivets
A Poor Design?
Current Application Techniques
Scaffolding
Human Equivalent of Airless
JPP* *Junior Painter Present
We always adhere to regulatory requirements?
Brushing (working into and around rivet heads)
Painters Mitt (for pipes & tubing)
Roller (for flat surfaces)
Why isn’t this man spraying?
Because his foreman’s car is in theparking lot downwind.
Airless Spray – High Transfer Efficiency
Some thick floor coatingsmust be toweled . . . .
ExitExit
Application benefits of 100% solids coatings:Little or no odor, no solvent emissions
Note:Applicators arewearing paperfilter masks,not organic
vapor masksfor PPE
Airless Pumps
Air DrivenPneumaticAirless Units
PluralComponentSpray Pump(Fixed Ratio)
For ElastomerUrethanes orPolyurea Ctgs
ProperVentilation:Use tubing tosuck air outfrom bottomcorners.All coatingsrequireventilationduring cure.
Dehumidification and Ventilation:Improves Quality of Blasting & Painting
BasicCoatings Technology
&Proper Selection of
Coatings
PNWS-AWWA2008 ANNUAL CONFERENCE
Stan OsborneSr. Industrial Coatings Specialist
ICI Devoe Coatings
Coating Fundamentals
What’s the Difference?
What’s the Difference????
“Paint” - usually associated with decorative oraesthetic uses.
“Coating” - usually associated with protectiveor functional uses.
What goes into a Can of Paint?
Resin
Pigment
Solvent
Additives
Can ofPaint
What Do Resins Do?
Binds pigmentation.
Provides film forming material.
Provides adhesion to substrate.
Generally defines generic coating type
What Do Pigments Do?
Provide :Opacity or hiding
Provide Color – TiO2 Titanium Dioxide(White), organic & inorganic liquid colorants
Barrier Pigments (dry) - platy talcs, MIO,aluminum, mica, etc. applied at factory
Anti-corrosive propertiesPhosphates, borates, zinc pigment
Extender Pigments (talc) – Cost reduction
What Do Solvents Do?
Dissolve the resin system andallow the liquid material to beapplied to a substrate
Provide fluidity and flow
Control “rate of dry” of the coating
Modify cure rate of some two packcoatings
Additives
Correct deficiencies in the coating formulation
Improve application performance
Improve sag resistance of applied film
Perform “miracles” as needed . . . .
To Be Useful, Paint or Coatings Must...
Be able to be applied to a substrate
Convert from a liquid to a solid film
Perform some desired function
How do Coatings Cure?
Solvent Evaporation
Coalescence (water base)
Reaction with Atmosphere(solvent base)
Oxidation
Moisture Cure
Reaction of Two Components(chemical crosslink)
Solvent Evaporation
Types: Lacquer, Vinyl
Solvent Solvent
Coalescence
Types: Latex (Acrylic, PVA)
CoalescingSolvent
CoalescingSolvent
HH22OOHH22OO
Atmospheric Reaction: Oxidation
OO22
OO22
OO22
OO22
OO22
OO22OO22
OO22
Types: Oil, Alkyd, Epoxy Ester, Urethane Alkyd
Atmospheric Reaction: Moisture Cure
HH22OOHH22OO
HH22OO
Ethyl Silicate Zinc Primer, Moisture Cured Urethane
Reaction of Two Components(chemical crosslink)
Polyurethane, Epoxy (Polyamide, Novolac, Amine)
How do Coatings Protect?
Barrier Protection
O2H2OSalt
Zinc AnodeSteel Cathode
H2O
Rust Inhibitive Pigment
Galvanic Protection
How do Coatings Adhere?
Chemical Adhesion
Mechanical Adhesion
++ -- ++ -- ++ --
- + - + - +Polar Adhesion
GenericCoatingsTypes
Generic Types
Zinc
Epoxy
Polyurethanes
Alkyds (oil base)
Acrylics (water base)
Specialties
Zinc-Rich CoatingsA Major Advantage
“Only zinc-rich coatings can eliminatepitting corrosion at voids, pinholes,scratches and abrasions. This protectivecapability makes zinc-rich coatings sounique.”
Why do we use Zincs?
Superior Corrosion Protection
Where do we use Zincs?
Where best corrosion protection is requiredIOZ and RIOZ & OZ are all effective
New construction – IOZ Shop Applied
Marine Environments – Severe Service
Maintenance - RIOZ & OZMore tolerance to lesser surface prep
Easier to apply in field
(Tanks, piping, structural steel that might experiencecoating system damage (scratching or chipping) aretypical applications)
Inorganic (IOZ)
Ethyl Silicate(solvent)
Lithium, sodium silicate (water)
Organic (OZ)Epoxy (solvent or water)
Moisture Cure Urethane (solvent)
Reinforced Inorganic (RIOZ)Hybrid with IOZ and OZ characteristics
(solvent)
(Proprietary Mfr’s – Limited Availability)
Types of Zinc Rich Coatings?
Limitations
IOZ
IOZ requires moisture to cure – no good in desertclimates or low humidity regions
Mudcracking if over applied – 5mils max dft
High Potential for bubbles in film when topcoating
OZ & RIOZ
Less heat resistance - 400°F v. 750°F
less solvent resistance - immersion
Organic vs InorganicZinc
Organic ResinCarbon backbone
C-C-C-C
Inorganic ResinSilicate backbone
Si-O-Si-O-Si
Stronger bonds: higher heatresistance
Easier to Apply Better CorrosionResistance
Ethyl Silicate InorganicZinc Primer:Bubbling Problems
High BuildHigh BuildProtectiveProtectiveCoatingCoating
Zinc PrimerZinc Primer(many voids(many voids ––
air pocketsair pocketsbetween zincbetween zinc
particles)particles) SteelSteel
Reinforced Inorganic Zinc Primer:No Voids - No Bubbles
RIO Zinc PrimerRIO Zinc Primer(Void Free(Void Free ––Zinc pigmentZinc pigment
Bound inBound inRIO matrixRIO matrix –– NoNoAir Entrapment)Air Entrapment)
High BuildHigh BuildProtectiveProtectiveCoatingCoating
SteelSteel
Reinforced Inorganic Zincs vsTraditional Inorganic Zincs (cont.)
Film is essentially void freeEliminates topcoat bubbling - No Mist/Tie coat of epoxy requiredDoes Not require humidity to proper cure (fast recoating)
Improved adhesion and flexibilityTolerates less surface preparation (SP-6)Can be recoated over itselfNo cracking on 90o bendHigh resistance to mud cracking
Lower heat & solvent resistanceResists 400F dry heat (vs 750F of traditional IOZ)Cannot be used as a tank lining for solvents
Reinforced InorganicZinc Benefit Summary
Improves Compatibility with many topcoats
Speeds up Recoat Time ( 30 Min. @ 75 0F)
Resists Splitting - excellent flexibility
Resists Mud Cracking – Less Rework
Reduces Salting (recoat months later )
Reduces Bubbling when topcoated - No EpoxyMist/Tie Coat required - A HUGE BENEFIT
Not Humidity Dependent – Use in Arid Climates
Why do we use Epoxies?(and what do they provide)
Excellent Adhesion
Superior Barrier Protection
Superior Corrosion Resistance
Excellent Chemical Resistance
Where do we use Epoxies?
When good barrier properties needed
New construction
Maintenance painting in the field
Tank Linings
Floor Coatings – Secondary Containment
Marine Environments
Designated by curing agent type
polyamines
polyamides
alkylated phenolic polyamines
Solvent and water based
Types of Epoxy Coatings?
“Polyamine Epoxy”Advantages
Water Immersion
Good Chemical Resistance
Good Acid Resistance
Fast Cure
Alkali Resistance
“Polyamine Epoxy”Limitations
Short pot life
Amine Sweat or Blush
CO2 and Water
Chalking, Fading, Yellowing, Etc.
“Polyamide Epoxy”Advantages
Surface Tolerance
Decent Recoatability
Adhesion and Wetting
More Tolerant of Surface Moisture
“Polyamide Epoxy”Limitations
Poor Exterior Exposure Resistance
Application Above 50°F
Limited Chemical Resistance
Chalking, Fading, Yellowing, Etc.
“Waterborne Epoxy”Advantages
Low Odor
Waterborne - Safety
Good Chemical Resistance
“Waterborne Epoxy”Limitations
Usually Not For Water Immersion
Application Above 50°F
Working Life versus Pot Life
No Surface Tolerance For Oil
Chalking, Fading, Yellowing, Etc.
Why Modify Epoxies?
To improve some particular characteristic
water resistance
weather resistance
flexibility
recoatability
reduce viscosity
“Coal Tar Epoxy”Advantages
Excellent Water Resistance
Good Acid Resistance
High Film Build Possible
“Historical Old School CoatingStandard” In Waste Water Treatment
“Coal Tar Epoxy”Limitations
Safety
Skin Burns
Carcinogenic
Bleeding of Light Topcoat Colors
Difficult to Recoat
Stability In Container is Poor
“Hydrocarbon Modified Epoxy -Coal Tar Offset”
Advantages
Formulated with synthetic hydrocarbon resin
Will not cause coal-tar burns
Improved water resistance
Improved can stability (1 year vs coal tar @ 6 months)
Improved recoatability (30 days vs coal tar @ 20 hrs)
“Synthetic” Tar TechnologyLower Material Cost
Coal Tar Performance Without
Coal Tar Associated problems
No Coal Tar Burns – Worker Safe
Not Carcinogenic Like Coal Tar
Superior Performance
Superior Application Elements
“Hydrocarbon Modified Epoxy-Coal Tar Offset”
Limitations
Like Coal Tar, Available Only In Black
Aromatic Backbone, Chalks And Turns GrayOn Exterior Exposure
“Hydrocarbon Modified Epoxy”Light Color Base
Advantages
Hydrocarbon Resin Improves water resistance
Non-bleeding so may be overcoated
Multiple Uses
Effective cost
“Hydrocarbon Modified Epoxy”Light Color Base
Limitations
Reduced Solvent And Chemical Resistance
Not able to provide long term Cosmetic Appeal
Aromatic backbone not UV resistant
“Alkylated Phenolic PolyamineModified Epoxy”
Advantages
True low temperature cure to 0°F,without use of deleterious cureadditives for temps below 50F
Excellent surface tolerance (power toolcleaning) even for water immersion
High Solids = High Build film buildcapability
“Alkylated Phenolic PolyamineModified Epoxy”
Limitations
Color changes (yellowing) more thanpolyamides
shorter recoat window due to low tempcure built into formulation
Not UV resistant
Please, Remember That...
Based on the Aromatic backbone, All EpoxyCoatings On Exterior UV Exposure will:
Chalk
Fade
Color Drift
This does not negatively affect corrosion protective performance
Why do we use Urethanes?
To Provide Excellent Color and Gloss Retention
When a structure needs to look good (cosmetics)
To provide abrasion resistance in the finish coatfor specific applications (ie: Floor Coatings)
Where do we use Urethanes?
Exterior applications for appearance andcosmetic appeal
New construction (shop & field)
Maintenance painting in the field
Interior applications for chemicalresistance properties
Can be used as finish coat for FlooringInstallations
Two Component Aliphatic Urethanes
Two Component Polyaspartic Polyurethane
Single Component Moisture Cure Urethanes
100% Solids Elastomer Polyurethane FastSet Coatings – Two Component
Types of Urethanes Coatings?
“Aliphatic Acrylic Polyurethane”Advantages
Maximum color and gloss retention
Excellent Ultraviolet Light (UV)resistance
Hard, mar & graffiti resistant finish
The “Ultimate” finish coat forcosmetic appeal and appearance
“Aliphatic Acrylic Polyurethane”Disadvantages
Poor Recoatability after maximumrecoat window is exhausted (requiresabrading)
Sensitive to surface moisture at timeof application
Relatively expensive (due toaliphatic backbone UV resistanceproperties)
“Polyaspartic Polyurethane”Advantages
Excellent color and gloss retention
Excellent Ultraviolet Light (UV)resistance
Very fast cure and return to service(much quicker than Aliphatic AcrylicPolyurethanes) 5hrs dry hard @ 70F
Atmospheric Humidity aides in fastcure and quick weather resistance
Suitable for floor finish with fastturnaround
“Polyaspartic Urethane”Disadvantages
Poor Recoatability aftermaximum recoat window isexhausted (requires abrading)
Sensitive to moisture onsurfaces at time of application
Relatively expensive (due toaliphatic backbone UVresistance properties)
“Single ComponentMoisture Cured Urethane”
Advantages
Single Package
Perceived as simple to apply under allconditions – (sometimes oversold)
Utilizes atmospheric humidity to dry
“Single ComponentMoisture Cured Urethane”
DisadvantagesPoor Recoatability – Inter-coat sensitivity
Requires atmospheric humidity to dry –trouble in low humidity climate zones
Critical Re-Coat windows (ie: MC Tar)
Overbuilding can create solvententrapment / micro blistering
Very Expensive Coating System whencompared to convention two pack systems
“Elastomer PolyurethaneFast Set Coatings”
AdvantagesVery Fast dry time (ie: 15 seconds to handle)
Fast Return to Service
Extremely High Film Build Capabilities viamultiple pass of spray gun
Elastomeric properties
100% Volume Solids – Very Low VOC
Relatively expensive – due to high films
“Elastomer PolyurethaneFast Set Coatings”
DisadvantagesPrimers recommended to wet out
substrate and provide high adhesion
High dry film thickness required to providechemical resistance – can delam in sheets
Very Sophisticated Plural SprayEquipment Required for Installation
Most manufacturer’s only have aromaticformulation (chalk, fade & lose gloss in UV)
Conventional Paints & Coatings
“Alkyd”(Oil/Solvent Base)
Advantages
Moderate Cost
Good color and gloss retention (3-4 yrs.)
Ease of application-brushing/rolling
Less critical surface preparation-goodwetting
Historical workhorse for Light DutyIndustrial installations
“Alkyd”(Oil/Solvent Base)
LimitationsSlow drying - skinning over - long oil
Poor chemical resistance
Relatively poor water resistance
Poor flexibility and impact resistance -short oil
High Humidity can negatively affect glossduring application/cure
Yellows and chalks in UV exposure
“ Silicone Modified Alkyd”(Oil/Solvent Base)
Advantages
Higher Cost than Alkyd Enamel (silicone additive 30%)
Good color and gloss retention (6+ yrs.)
Ease of application-brushing/rolling
Less critical surface preparation-good wetting
Silicone Modification improves resistance toYellowing and chalking in UV exposure
Historical workhorse for Military/Marine ExteriorUV installation
“Silicone Modified Alkyd”(Oil/Solvent Base)
Limitations
Slow drying - skinning over - long oil
Poor chemical resistance
Relatively poor water resistance
Poor flexibility and impact resistance -short oil
High Humidity can negatively affect glossduring application/cure
“Epoxy Ester”Advantages
Abrasion Resistance
Chemical Resistance Better Than Alkyd
Ease of application-brushing/rolling
Less critical surface preparation-wetting – tolerates rusty surfaces
Single package for ease of use
“Epoxy Ester”Limitations
Poor Color And Gloss Retention On Exterior
More Expensive Than Alkyd
Color will drift in UV Exterior Exposure
“Waterborne Acrylics”Advantages
Safety - Waterbased - Low Odor
Excellent Color and Gloss Retention
Wide Range of Colors Via Tint Bases
Fast Dry
Usually Rather Flexible
“Waterborne Acrylics”Limitations
Usually Require Temperatures Above 50°F
Not Abrasion Resistant
Temperature Resistance 200°F max.
Not Much Chemical Or Water Resistance
High Humidity retards drying and cure
Does Not provide Equivalent Performanceof an Aliphatic Polyurethane Two PackProduct
UV Resistance of Topcoats(Gloss and Color Retention)
UV ResistanceUV Resistance
AlkydAlkyd FairFair 33 –– 44LatexLatex GoodGood 66 -- 88Modified SiliconeModified Silicone11 GoodGood 66 -- 99EpoxyEpoxy PoorPoor 11 -- 22PolyurethanePolyurethane ExcellentExcellent 99 -- 1212Vinyl/Chlor RubVinyl/Chlor Rub GoodGood 66 -- 88Pure SiliconePure Silicone ExcellentExcellent 99 -- 1212
Aesthetic Life (Years)Aesthetic Life (Years)
1. Modified Silicone = Silicone Alkyd or Silicone Acrylic1. Modified Silicone = Silicone Alkyd or Silicone Acrylic
PNWS-AWWA2008 ANNUAL CONFERENCE
Stan OsborneSr. Industrial Coatings Specialist
ICI Devoe Coatings
THANK YOUFOR YOUR INTEREST & ALLOWINGDEVOE COATINGS TO ASSIST WITH
PROTECTING YOUR FACILITIESASSETS
ICI PAINTSDEVOE COATINGS
Contact Information:
Washington/Alaska/Idaho/MT/WY
Stan Osborne
Phone: (253) 209-3120
Email: [email protected]
Fax: (253) 471-9130
Contact Information:Contact Information:
Oregon StateOregon State
Ron WattsRon Watts
Phone: (541) 673Phone: (541) 673--00190019
Email: [email protected]: [email protected]
Fax: (541)673Fax: (541)673--00190019